Ultradyne UD Spigot OD Green. 25 inches of perfectly aligned Arca rail capacity. The M-LOK slots also make it possible to attach additional accessories including Picatinny rails. It is machined from 6061 T6 aluminum with a hard anodized finish. Specifications for Ultradyne UD Spigot Tactical Rail: Manufacturer: Ultradyne Finish: Hardcoat anodize Fabric/Material: 6061-T6 Aluminum Gun Rail: M-LOK Cant: Straight Hand: Ambidextrous Length: 4.75 in Width: 1.5 in Height: 0.448 in Weight: 2.8 oz Last Chance: Yes Package Contents: Ultradyne UD Spigot Tactical Rail Ultradyne UD13004-OG: UD Spigot OD Green